Process and apparatus for separating floating solid material from liquids

Abstract: In a solid material flow-separating method for separating fine solid material from fluid, plural massive, net-shaped or pipe-shaped flow-separating members each having opening portions of about 1 to 5cm in equivalent diameter are disposed along a fluid flowing direction in a treatment tank, and the fine solid material floating in the fluid is trapped and collected through the opening portions, and held up in a predetermined area, thereby separating the fine solid material from the fluid.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for separating floating fine solid material from liquid, particularly to a method for separating floating fine solid material from liquid for conducting a separation treatment on fine solid material in liquid, and more particularly to a method for separating fine solid pollutant floating in polluted water. 2. Description of Related Art Various kinds of methods have been conventionally proposed and used to purify polluted water such as various kinds of waste water, river water polluted by the waste water, etc. For example, FR-A-1 578 228 discloses a method for purifying polluted water, wherein the polluted water flows from a distribution chamber of a tank through several adjacent horizontal tubes and is collected in another chamber at the discharge end of the tubes. Particles suspended in the polluted water are deposited on the lower surfaces of the tubes, so that purified water leaves the tubes into the chamber at the end of the tubes. Furthermore, DE 31 49 545 C1 discloses an apparatus for separating suspended particles from fluids, wherein thick walls arranged parallel to the flowing direction comprise a plurality of channels formed perpendicular to the flowing direction. Particles suspended in a fluid, particular gas, tend to flow towards the region adjacent to the walls and into the openings of the channels and are separated from the fluid as soon as they move into the channels. However, the channels have a diameter of at the most 10 mm so that they are not suitable for separating solid material from liquid fluids. Furthermore, due to the required thickness of the walls in order to avoid turbulences passing through the channels this known method requires an apparatus of complicated structure. Finally, DE-A-24 49 355 discloses a method and an apparatus for changing the concentration of suspended materials, wherein energy, such as vibration is applied to the suspended material and the resulting movement of the suspended material is used for separating the suspended material. This method also requires a complicated apparatus and cannot provide an economic method for separating floating fine solid material from liquid. Other known purifying methods for the polluted water are mainly classified into the following two methods. One method is (1) a chemical treatment method in which pollutant in polluted water is subjected to a chemical treatment to make the pollutant harmless, and the pollutant is agglomerated and precipitated to separate the pollutant from the water, and the other method is (2) a biological treatment method in which the pollutant is biologically made harmless, for example, by a biomembrane or active sludge, and then the pollutant is flocculated to separate the pollutant from the water. In most of recent biological treatments, a microorganism is fixed to a prescribed carrier to form a biomembrane. In order to form the biomembrane have been proposed a method of alternately disposing aerobic state and anaerobic state on the carrier, and a method of simultaneously disposing aerobic state and anaerobic state on a carrier to form a hollow carrier as disclosed in Japanese Laid-open Patent Application No. 63-310696. Further, for the purpose of purification of polluted river water, an inter-conglomerate contact oxidation method of purifying river water using river beds has been recently proposed and already practically used as a biological treatment method. In the inter-conglomerate contact oxidation method, a conglomerate layer is formed by effectively using conglomerate such as gravel in river or the like, and river water is made to flow through the conglomerate layer for a biological treatment. By this method, BOD (Biochemical Oxygen Demand) and SS (Suspended Solid) can be greatly reduced, and thus spotlight of attention is focused on this method as a purification method for polluted water such as polluted river water. Any one of the conventional polluted water purifying methods as described above requires two steps of treatments of a reaction treatment system and a precipitation/separation treatment system in both of the chemical treatment and tire biological treatment. The inventor has made various studies on purification for polluted water in a water system such as a river. Particularly for the purpose of improvement in practicability by effectively using the inter-conglomerate contact oxidation method, the applicant has considered an improved technique to the inter-conglomerate contact oxidation method, and developed a separation material constituting a purifying treatment system which is completely different from the conventional treatment for polluted water. This separation material and a polluted-water treatment using the separation material are proposed in Japanese Laid-open Patent Application No. Hei-3(1991)-221110. SUMMARY OF THE INVENTION An object of this invention is to provide a method for separating floating fine solid material from liquid using an apparatus such as one or more separating members of simple construction and to provide such a separating apparatus in order to allow easy and simple separation and collection of floating fine solid material in liquid as well as to provide a corresponding use of a separating member. Another object of this invention is to provide a method of separating and removing SS (suspended solid) in polluted water such as polluted river water more effectively and efficiently to thereby purify the polluted water. In order to attain the above objects, the inventor has earnestly considered the action of polluted-water purification, etc. on the basis of the knowledge on a phenomenon, etc. which is obtained through the development of the separation material as described above. Through this consideration, the inventor has thrown light upon the behavior of floated fine solid material in fluid, and implemented this invention. The method for separating floating fine solid material from liquid is defined in independent claims 1 and 3. According to the solid material flow-separating method of this invention, the fine solid polluted material floating in the polluted water may be separated while it flows, and further fluidized to conduct a purifying treatment on polluted water. The separating apparatuses according to the invention are defined in independent claims 10 and 13. Finally, the use of a separating member according to the invention is described in claim 14. According to this invention, the flow-separating member as described above may be disposed in a housing which has both of a flow-in portion and a flow-out portion and has any lid or no lid, and through which the liquid flows, thereby forming a flow-separating apparatus, and the liquid is allowed to flow through the flow-separating apparatus to perform a solid-material flow-separating treatment. In this invention, the term "collected and held up" means that the fine solid material floating in liquid is trapped at the opening portions of the flow-separating member, and collected and held up in a predetermined area. Further, in this invention, the term "flow-separation" means the phenomenon of an action that solid material is separated from liquid through an interaction between the flow of the liquid and the solid material floating in the liquid. The flow-separating member of this invention which is disposed in the liquid acts as a resistor in the liquid, and it serves to reduce flow velocity of the liquid in the vicinity of the flow-separating member, thereby forming a laminar-flow area. Therefore, there occurs any different in flow velocity in the liquid. Solid material floating in the liquid having any flow-velocity difference is shifted toward an area having low flow velocity with being rotated, finally reaches the laminar-flow area surrounding the flow-separating member, and collected at the area. It has been well known that a low flow-velocity or zero flow-velocity area and a turbulent-flow area exist as a flow state of the liquid. The fine solid material floating in the turbulent-flow area trends to be sprung out toward the laminar-flow area by random flow, so that the fine solid material is integrated (collected) in the laminar-flow area which is formed surrounding the flow-separating member. As described above, the fine solid material reaching the flow-separating member is trapped and collected at the opening portions each having large aperture of more than 1 to 5cm. The shape of each opening portion of this invention is not limited to a specific one. For example, curved shape such as circle, ellipsoid, sector or the like, polygonal shape such as triangle, rectangle or the like, or irregular shape which is not specified because of its complicated and irregular shape, or the like may be used. When the opening portion has the irregular shape, the inscribed circle diameter may be set to more than 1 to 5cm. If the diameter of the opening portion of the flowseparating member exceeds 5cm, some flow occurs in the opening portion, and this flow disenable the floating fine solid material to be trapped and collected inside of the opening portion. After trapped by the opening portion, the fine solid material is held up in the flow passageway under the opening portion, and then decomposed in anaerobic state to be fluidized. Thereafter, the fluidized material is passed through another intercommunicated opening portion by its weight or gravity and discharged to the outside of the flow-separating member. At this time, if the opening portion is designed in smaller diameter than 1cm, the decomposed fluidized material is not discharged to the outside of the flow-separating member, and thus such small diameter is unfavorable. The liquid entering the inside of the opening portion of the flow-separating member is kept in the hold-up state where the flow velocity is substantially equal to zero, and the trapped fine solid material is collected and held up in the flow passageway of the massive member, at the bottom portion of the inside of the cylindrical member or in the closed area provided at the one side of the net in accordance with an used mode of the flow-separating member, thereby separating the fine solid material floating in the liquid. The fine solid material which is trapped and collected in the flow passageway of the massive member is decomposed to fluidized material in an anaerobic state, then moved along the flow passageway penetrating through the massive member by its weight, and then discharged through another opening portion to the outside. In this case, if considering, from the viewpoint of the micro, the flow state when the fluidized material obtained by discomposing the trapped floating solid material in the anaerobic state is discharged, the flow passageway would be temporarily changed from the hold-up state to the flow state, and thus it is guessed that the fine solid material reaching from the liquid to the opening portion can be taken into the flow passageway again to collect and hold up the fine solid material. That is, the flow-separation, trapping, collection, fluidization, etc. are repeated for the fine solid material to enable purification of polluted water, etc. In the cylindrical flow-separating member, by forming a slender groove at the bottom portion on which the cylindrical member is disposed, the fine solid material which is collected and held up at the bottom portion may be discharged as fluidized material through the groove like the massive flow-separating member as described above, or the collected fine solid material may be successively extracted out. Further, in the net-shaped flow-separating member, the fine solid material which is collected and held up in the closed area can be treated in the same manner as the hollow cylindrical flow-separating member. According to this invention, the massive member having prescribed opening portions, the barrel-shaped member or the net-shaped member is used as the flow-separating member, and the fine solid material is separated from the liquid. In this construction, microorganism such as bacteria is liable to adhere to the surface of the flow-separating member disposed in the liquid, so that the roughness of the surface of the flow-separating member is increased. Accordingly, a boundary layer occurring on the surface of the flow-separating member, that is, a layer area where the flow velocity is low or zero is enlarged, and the flow separation of the fine solid material can be promoted by the velocity difference and/or the flow state as described above. In the conventional solid/liquid separation method, active sludge and coagulant are used for a sewerage and waterworks respectively to grow hardly-precipitated fine solid to a predetermined size and make it precipitable solid material, and then the solid material thus obtained is precipitated or filtered. On the other hand, according to this invention, as described above, the flow-separating member is disposed in the liquid, and the solid/separation is carried out utilizing the flow-velocity difference for the fine solid material. Accordingly, this invention can be substituted for the conventional solid/liquid separating method containing the growth and precipitation or filtering of the fine solid material. According to the inventive method and apparatus thus constructed, the solid material can be easily separated from the liquid and collected by utilizing rotational movement of the fine solid material due to the flow-velocity difference occurring at a surrounding area of the fine solid material and the viscosity of the liquid. In addition, according to this invention, not only the fine solid material floating in the liquid is separated and removed, but also BOD, etc. can be reduced in a polluted water treatment. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view, partially containing a cross-sectional view, showing the apparatus showing an embodiment of a apparatus equipped with a flow-separating member of this invention; Fig. 2 is a schematic view of an embodiment of a massive flow-separating member of this invention; Fig. 3 is a schematic view, partially containing a cross-sectional view, showing another embodiment of the apparatus equipped with the flow-separating member of this invention; Fig. 4 is a schematic view, partially containing a cross-sectional view, showing another embodiment of the apparatus equipped with another flow-separating member of this invention; Fig. 5 is a schematic view, partially containing a cross-sectional view, showing another embodiment of the apparatus equipped with the flow-separating member of this invention; Fig. 6 is a schematic view showing an embodiment of a hollow flow-separating member (barrel or cylindrical shape); and Fig. 7 is a schematic view showing another embodiment of the hollow flow-separating (square pole shape). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments according to this invention will be described with reference to the accompanying drawings, however, this invention is not limited to the following embodiments. Fig. 1 is a schematic diagram showing an embodiment of a apparatus equipped with a flow-separating member of this invention, partially containing a cross-sectional view of the apparatus, and Fig. 2 is a schematic view of a massive flow-separating member disposed in the apparatus as shown in Fig. 1. In Fig. 1, a liquid flowing apparatus 10 comprises a treatment tank 1 of rectangular parallelopiped shape, and the treatment tank 1 has no lid, but both swalls 3 in a longitudinal direction thereof. The bottom portion 2 of the treatment tank 1 is so designed to be downwardly slanted from the both walls 3 to the center portion of the tank 1, and a slender groove 4 is formed at the center portion of the bottom portion 2 of the treatment tank 1 to extend in the longitudinal direction of the tank (in the flowing direction of the liquid). A flow-separating member 5 as shown in Fig. 2 is disposed substantially over the whole inside area of the tank 1 to form a flow-separating member layer 50. The treatment tank 1 is further provided with a flow-in portion 6 for the liquid at one end in the longitudinal direction of the tank 1, and with a flow-out portion (not shown) at the other end, thereby allowing the liquid to flow from the flow-in portion 6 to the flow-out portion. The flow-separating member 5 as shown in Fig. 2 is formed as follows. That is, aggregate particles 7 each having equivalent diameter of several centimeters are fixed to one another with adhesive agent such as cement, epoxy adhesive agent or the like in substantially spherical shape to form a spherical massive member of about 7 to 15 cm in equivalent diameter. A gap interval between the fixed aggregate lumps 7 is varied in accordance with the size of the aggregate particles 7, and thus a desired gap interval can be obtained by suitably selecting the size of the aggregate particles 7. Usually, if the aggregate particles are designed in centimeter order size, the gap interval could be set to about 1 to 3cm. Those gaps which are formed as described above and located on the surface of the massive member 5 serve as opening portions 8, and those gaps which are formed as described above and located in the massive member 5 serve as flow passageways which are penetrated through the massive member 5 and continuously intercommunicated with any opening portion 8. In the liquid flow apparatus 1 thus constructed, liquid such as polluted water or the like which contains floating fine solid material therein is made to flow from the flow-in portion 6 in the longitudinal direction of the treatment tank 1 as indicated by an arrow in Fig. 1, thereby reducing the flow-velocity of the flowing water in the vicinity of each flow-separating member 5. Therefore, the fine solid material floating in the flowing water is moved toward the nearest flow-separating member while being rotated due to the difference of the flow velocity at the right and left sides, arrives at the flow-separating member, and then separated from the flowing water. The separated fine solid material are trapped on the surface of the flow-separating member, taken in the recessed opening portions, and then collected and held up in the flow passageways at the gaps between tile aggregate particles. Further, organic solid material which is mixed in the fine solid material held up in the flow passageway inside of each flow-separating member is decomposed in the anaerobic state to be fluidized, and then discharged from each flow-separating member by its weight or gravity. The fluidized material thus discharged falls down to the bottom portion 2 of the tank, and is collected in the slender groove 4 provided at the bottom portion to be discharged to the outside of the tank. Fig. 3 is a schematic view, partially containing a cross-sectional view, showing another embodiment of the apparatus equipped with the spherical massive flow-separating member as described above. The construction of the this embodiment is similar to that of the embodiment as shown in Fig. 1, except that the flow-separating members 5 are arranged in stripe form in parallel to the flowing direction to form striped flow-separating member layers 50 in the tank as shown in Fig. 3. In this case, each flow-separating member acts in the same manner as described above to separate the floating fine solid material from the flowing polluted water and collect and store the separated fine solid material. In addition, since the flow velocity of the flowing polluted water is reduced in the neighborhood to the flow-separating member layers 50 in flow spaces 51 between the flow-separating member layers 50, the floating fine solid material in the polluted water flowing through the flow spaces 51 is rotationally moved toward the flow-separating member layer 50 as described above. The fine solid material reaches the surface of the flow-separating member, and separated, collected and held up in the flow passageways. Further, the organic solid material is also decomposed and fluidized, and collected in the slender grooves 4 in the same manner as described above. In this case, the slender groove 4 is formed at the bottom portion 2 of the tank 1 so as to positionally correspond to each flow-separating member layer 50. The flow-separating member which is formed of aggregate particles each having small diameter is apparently regarded as being identical to a biomembrane carrier as proposed in Japanese Laid-open Patent Application No. 63-310696. However, the biomembrane carrier as proposed in the above publication is a hollow member having inner space therein, and ultra-fine holes of 0.05 to lmm diameter are formed in the surface of the hollow member so as to be intercommunicated with the inner space. Therefore, each ultra-fine hole is not regarded as being (continuously) penetrated through the biomembrane carrier, and thus the biomembrane carrier is completely different from the flow-separating member of this invention. In addition, the above publication describes that sludge is held in the inner space of the carrier. However, it is impossible for the sludge to be discharged through the ultra-fine holes to the outside by its weight, and in this point the above membrane carrier is different from the flow-separating member of this invention. Further, the above publication discloses a carrier having fine holes as a prior art, however, the construction of the fine holes is unclear. Fig. 4 is a schematic view, partially containing a cross-sectional view, showing another embodiment of the apparatus equipped with another flow-separating member of this invention. The construction of this embodiment is similar to that of the embodiment as shown in Fig. 1, except that a pair of net-shaped flow-separating members 15, each comprising a net having apertures of about 1 to 3cm, are disposed in parallel to each other at both side walls 3 of the tank 1 in the longitudinal direction of the liquid flow apparatus 10 respectively as shown in Fig. 4. The same elements as those of Fig. 1 are represented by the same reference numerals. The arrangement of the net-shaped flow-separating member in the apparatus is made so that the net-shaped flow-separating member is disposed near to each side wall 3 3 of the tank 1 so as to form a space between the side wall 3 and the net-shaped flow-separating member 15. With this arrangement, a storage area 16 where the fine solid material is collected and held up can be formed at one side of each net (between the net 15 and the side wall 3) using the peripheral walls of the apparatus. For example when the treatment tank of the liquid flow apparatus is designed to have about 60cm width, each storage area 16 is designed to have about 15cm width, and usually it is preferably designed to have the width equal to or less than about quarter of the full width of the treatment tank. Further, the material of the net-shaped flow-separating member is not particularly limited, and it may be formed of metal, synthetic resin or the like. The flow velocity of the liquid is reduced in the neighborhood of the net-shaped flow-separating member 15 by action of the net-shaped flow-separating member 15. Accordingly, in the same manner as described above, due to the flow-velocity difference occurring at both sides of the solid material, the fine solid material floating in the liquid is rotationally moved to an area where the flow velocity is lower, finally reaching the net-shaped flow-separating member 15. Thereafter, the solid material is taken in the (stagnant) storage areas 16 through the net apertures 18 serving as the opening portions, and collected and held up. The collected and held up solid material is precipitated, and discharged to the outside through slender grooves 14 for collection and removal. The following modification may be made to the above construction. That is, recessed member is formed in a stripe form so as to meet the flowing direction of the treatment tank 1, and a net is put up at the open side of the recess portion to form a net-shaped flow-separating member using a recessed space as a storage area. A plurality of net-shaped flow-separating members thus constructed are disposed in parallel to the flowing direction in the treatment tank 1 as shown in Fig. 3. In this case, the array of these net-shaped flow-separating members may be used in combination with the storage areas formed at both side walls. Fig. 5 is a schematic view, partially containing a cross-sectional view, showing another embodiment of the apparatus equipped with another flow-separating member of this invention, and Figs. 6 and 7 are schematic views of the pipe-shaped (hollow cylindrical shape and hollow rectangular parallelopiped shape, respectively) flow-separating members disposed in the apparatus a shown in Fig. 5, respectively. As shown in Fig. 5, a plurality of hollow cylindrical or hollow rectangular parallelopiped flow-separating members 25 having small holes serving as opening portions 28 as shown in Fig. 6 or 7 are arranged in row (in array form) substantially in parallel to both side walls of the tank 1. A slender groove 24 is formed at the bottom portion of each array of the pipe-shaped flow-separating members 25. Tile fine solid material floating in the liquid is separated from the liquid, falls down toward the bottom side to be collected and held up inside of the pipe-shaped flow-separating members 26, and then discharged through the slender grooves 24 to the outside. The other construction than as described above is similar to the construction as shown in Figs. 1, 3 and 4. In the following description, the same elements as those of Fig. 1 are represented by the same reference numerals. The actions such as collection, storage, etc. of the floating fine solid material when the liquid such as polluted water or the like is made to flow in the treatment tank 1 are identical to those of the embodiments as described above. The flow-separating members 25 as shown in Figs. 6 and 7 are designed in cylindrical and rectangular parallelopiped shapes respectively, and are formed on the peripheral walls thereof with various shapes of small holes having equivalent diameter of more than 1 to 5 cm, such as circular holes and rectangular holes respectively. The shape, arrangement and number of the small holes are not limited to specified ones, and they may be selected in accordance with an applicable condition. The sectional shape of the pipe-shaped flow-separating member is not limited to a specific one, and usually circular and rectangular shapes are used. Further, the material of the flow-separating member is not limited to specific one, and synthetic resin or metal is usually used. EXAMPLES (Embodiment 1) Conglomerate particles of about 2 to 3 cm were fixed to one another to form a spherical flow-separating member 5 having equivalent diameter of about 10cm (which is similar to that of Fig. 2). These spherical flow-separating members 5 thus formed were filled in a rectangular parallelopiped treatment tank of 0.5m in width, 4.0m in length and 0.5m in height, thereby forming a liquid flow apparatus 10 similar to that of Fig. 1. In this case, the percentage of voids of the flow-separating member layer was 45%. Polluted water of 20.9 mg/l in SS, as water to be treated, was made to flow into the liquid flow apparatus 10 thus formed for a hold-up time of 0.5 hour at flow amount of 0.3 1/second. As a result, the flowing water after five hours elapsed had average value of 5.7mg/l in SS, and thus a removing rate of SS was 72.7%. The polluted water had 15mg/l in BOD, and it was reduced to 4.5mg/l after the flow-separating treatment. (Embodiment 2) As shown in Fig. 4, metal meshes having aperture of 1cm were disposed in a rectangular parallelopiped treatment tank of 0.6m in width, 50.0m in length and 0.5m in height so as to be located away from the both side walls of the tank in the longitudinal direction by 15cm and so as to be in parallel to the both sides and in the same height as the flowing liquid, thereby forming a liquid flow apparatus 10 having the flow-separating member as shown in Fig. 4. The same polluted water as the embodiment 1, that is, polluted water of 20.9 mg/l in SS, as water to be treated, was made to flow into the liquid flow apparatus 10 thus formed at flow velocity of 30cm/s and flow amount of 90 l/second. As a result, the flowing water after 48 hours elapsed had average value of 15mg/l in SS, and thus the removing rate of SS was 30%. (Embodiment 3) Small circular holes of 10mm in diameter were formed at about 5mm interval in a hollow cylindrical member of 10cm in outer diameter to form a cylindrical flow-separating member. Totally, 37 flow-separating members 25 thus formed were disposed at about 10cm interval in a rectangular parallelopiped treatment tank of 0.5m in width, 4.0m in length and 0.5m in height to form a liquid flow apparatus 10 similar to that of Fig. 5. Polluted water of 8.0 mg/l in SS, as water to be treated, was made to flow into the liquid flow apparatus 10 thus formed for a hold-up time of 0.3 hour at flow amount of 0.8 1/second. As a result, the flowing water after 48 hours elapsed had average value of 4mg/l in SS, and thus the removing rate of SS was 50%. As is apparent from the embodiments as described above, according to the solid material flow-separating method and apparatus of this invention, the fine solid material floating in the liquid is rotationally moved by the viscosity (sheer stress) of the liquid and the flow-velocity difference occurring at the surface area of the solid material, whereby the solid material can be easily separated from the liquid and collected. Further, not only the separation and removal of the fine solid material can be performed, but also reduction of BOD or the like can be performed in a treatment for polluted water.

Claims: A method for separating floating fine solid material from liquid, comprising the steps of: disposing plural separating members made from flat sheet like material, whose surfaces are in use at least partially in contact with liquid and have opening portions with an equivalent diameter greater than 1 cm and less than about 5 cms, in flowing liquid; and collecting and holding up the fine solid material floating in the liquid through the opening portions in a predetermined area located at the bottom portions of the separating members or formed by a closed area, for which at least partially the separating members serve as a boundary, thereby separating the fine solid material from the liquid. The method as claimed in claim 1, wherein the liquid is polluted water, and further comprising the steps of collecting and holding up fine solid pollutant floating in the polluted water, thereby performing purification treatment for the polluted water. A method for separating floating fine solid material from liquid, comprising the steps of: disposing plural massive separating members, whose surfaces are in use at least partially in contact with flowing liquid, the separating members being formed of plural aggregate particles with gap intervals between the particles, the gap intervals forming first opening portions on the surfaces of the separating members, whose equivalent diameter is greater than 1 cm and less than about 3 cms, the gap intervals furthermore forming plural flow passageways which are continuously penetrated to second opening portions on the surfaces of the separating members also formed by the gap intervals; and collecting said fine solid material floating in the liquid through said first opening portions and holding up said fine solid material in said flow passageways. The method as claimed in claim 3, wherein said massive members are arranged in stripe form in parallel to the flowing direction to form striped separating member layers, and wherein a slender groove is formed at the bottom of each of said layers. The method as claimed in claim 3 or 4, wherein the liquid is polluted water, and the collected and help-up fine solid material is fluidized, thereby performing purification treatment for the polluted water. The method as claimed in claim 1 or 2, wherein said separating member comprises a pipe-shaped member having opening portions on the peripheral surface thereof, and is disposed in the liquid with its axis in a direction vertical to the liquid direction, the fine solid material floating in the liquid being trapped and collected through said opening portions and held up inside of said pipe-shaped member. The method as claimed in claim 6, wherein said pipe-shaped members are arranged in at least one row in parallel to the flowing direction, and wherein a slender groove is formed at the bottom of each of the rows. The method as claimed in claim 1 or 2, wherein said separating member comprises a net-shaped member which is disposed in parallel to the flow direction of the liquid and has apertures serving as opening portions, and a closed area disposed in parallel to said net-shaped member, the fine solid material being trapped and collected through said opening portions of said net-shaped member and held up in said closed area. The method as claimed in any one of claims 1 to 8, wherein a separating apparatus includes a housing which has a flow-in portion and a flow-out portion, and is equipped with no lid or any lid through which the liquid flows, and said separating member is disposed in said separating apparatus, the liquid being made to flow through said separating apparatus to perform a treatment for separating floating fine solid material. A separating apparatus, for use within a method according to one of the above claims, comprising a flow-in portion, a flow-out portion and at least one separating member made from flat sheet like material, whose surfaces are in use at least partially in contact with liquid and have opening portions with an equivalent diameter greater than 1 cm and less than about 5 cms. A separating apparatus according to claim 10, characterized in that the separating member at least partially serves as a boundary for a closed area in which fine solid material can be collected. A separating apparatus according to claim 10 comprising a pipe-shaped separating member having opening portions on the peripheral surface thereof, at the bottom portion of which fine solid material can be collected. A separating member, for use within a method according to one of the above claims, whose surfaces are in use at least partially in contact with liquid, the separating member being formed of plural aggregate particles with gap intervals between the particles, the gap intervals forming first opening portions on the surface of the separating member and plural flow passageways which are continuously penetrated to second opening portions on the surface of the separating member, wherein the opening portions have an equivalent diameter of greater than 1 cm and less than about 3 cms. Use of a separating member made from flat sheet like material, whose surfaces are in use at least partially in contact with liquid and have opening portions with an equivalent diameter greater than 1 cm and less than 5 cm, for separating floating fine solid material from liquid. Use according to claim 14, characterized in that the separating member is a net-shaped member. Use according to claim 14, characterized in that the separating member is a pipe-shaped member having opening portions at the peripheral surface thereof.

Inventors: ETO SHUNJI, ETO, SHUNJI, ETO, SHUNJI, C/O AQUATECH, LTD.
Applicants: AQUATECH LTD, AQUATECH, LTD.
Application year: 1994
Main classification: B01D21
IPC codes: B01D21, C02F3, B01D39